A rectangular poster is 5 dm long and 3 dm wide. Sara wants to paint the whole poster. Find the area of the poster in square cm.

Step-by-step explanation:

Area = Length × Width

→ Identify the length and width

Length = 5 and Width = 3

→ Substitute in the values

Area = 5 dm × 3 dm

→ Convert into cm

Area = 50 cm × 30 cm

→ Simplify

1500 cm²

x = ±sqrt(10)

step-by-step explanation:

5 - 2x² = -15

subtract 5 from each side

5-5 - 2x² = -15-5

-2x^2   = -20

divide by -2 on each side

-2x^2   /-2= -20/-2

x^2 =10

take the square root on each side

sqrt(x^2 )=±sqrt(10)

x = ±sqrt(10)

check:

5 - 2x² = -15

+sqrt(10)

5 - 2(sqrt(10))² = -15

5 -2(10) = -15

5 -20 = -15

-15 = -15

-sqrt(10)

5 - 2(-sqrt(10))² = -15

5 -2(10) = -15

5 -20 = -15

-15 = -15